1. Field of the Invention
The field of the present invention is gas turbine engines of the type in which the turbine rotor is driven for rotation by the combustion gas generated in the combustor, and more particularly, gas turbine engines of the type provided with a heat exchanger which utilizes the thermal energy of the combustion gas to heat air to be supplied to the combustor.
2. Description of the Prior Art
Generally, gas turbine engines are roughly grouped into a single shaft type in which one turbine shaft is commonly used for driving a compressor rotor and for producing an output, and a two-shaft type (a multi-shaft type) which is separately provided with a high pressure turbine shaft for driving the compressor rotor and a low pressure turbine shaft for producing the output. In either type of gas turbine engine, the layout of the heat exchanger thereof greatly influences the layout of the turbine shaft and the compactness of the casing, imparting a large restriction to the freedom of design of the gas turbine engine.
For example, in Japanese Patent Application Laid-Open No. 244121/89, there is disclosed a two-shaft type gas turbine engine having the high pressure turbine shaft and the low pressure turbine shaft disposed in series, wherein two heat exchangers are arranged parallel with the turbine shaft at a radial outer position of a turbine rotor to thereby avoid an interference between the turbine shaft and the heat exchangers.
Furthermore, Japanese Patent Application Laid-Open No. 4173/83 discloses a single shaft type gas turbine engine, wherein the heat exchanger is arranged axially externally of that end of the turbine shaft closer to the turbine rotor so as to be perpendicular to said turbine shaft, and the output is produced from the other end of the turbine shaft closer to the compressor rotor so as not to interfere with the heat exchanger.
In addition to the layouts of the aforementioned heat exchangers, the layout of a combustor for generating a combustion gas and of a collector housing for collecting the combustion gas which has driven the turbine rotor is important, and such layouts are important factors in achieving a compactness of the engine.